Vol 24, No 2 (2025)

The development of cell therapy methods for T-lineage acute lymphoblastic leukemia remains a relevant clinical challenge. The current study presents a preclinical stage of anti-CD5 CAR-T cell development without the use of additional genetic modifications, relying on down-regulation of CD5. The resulting cell products demonstrated sufficient expansion rates and CAR expression levels, the predominance of the Tem phenotype (CD197–CD45RA–) and low expression of exhaustion markers (PD-1, CD57, TIGIT). The antitumor function was confirmed both in vitro through the assessment of degranulation, cytokine production, and cytotoxicity against the Jurkat cell line, and in vivo through the evaluation of CD5+ leukemia elimination in a murine model. The data obtained may serve as a basis for the development of a clinical manufacturing protocol for anti-CD5 CAR-T cells. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology.

High-dose post-transplant cyclophosphamide (PTCy) is an established method for the prevention of graft-versus-host disease (GVHD) in allogeneic hematopoietic stem cell transplantation (HSCT) from haploidentical donors, however data on its efficacy in the pediatric population remain limited. In this prospective study, we evaluated an improved PTCy-based GVHD prophylaxis regimen comprising the a4b7 integrin blocker vedolizumab and a co-stimulatory signal inhibitor abatacept in addition to standard treatment with PTCy and cyclosporine A. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation. Allogeneic HSCT was performed in children with high-risk acute leukemia in complete remission from a haploidentical (n = 54) or unrelated (n = 4) donor. Myeloablative conditioning was based on treosulfan or total body irradiation. In 97% of cases, bone marrow was used as a graft source. The engraftment rate was 98%. The cumulative risk of acute GVHD grade II-IV and III-IV was 38% and 8.6%, respectively, of acute intestinal GVHD grade II-IV - 10%, and of chronic GVHD - 7%. Transplant-related mortality after 2 years of follow-up was 3.6%, the incidence of relapse was 16%, the overall survival rate - 91%, and the event-free survival rate - 85%. Overall, the proposed GVHD prophylaxis regimen demonstrated a favorable safety profile and good tolerability, no specific adverse events were observed.

Despite the high effectiveness of hematopoietic stem cell transplantation (HSCT) in children with acquired aplastic anemia (AAA), the procedure can still result in such major issues as graft failure and rejection. Risk factors for graft rejection and poor function as well as the persistence of mixed chimerism include allosensitization, insufficient number of transplanted cells and relatively preserved native myelopoiesis. Long-term engraftment can be achieved by modifying conditioning and immunosuppressive therapy. One such promising approach is the inclusion of melphalan in a conditioning regimen. In our study, we retrospectively analyzed outcomes of HSCT with melphalan-based conditioning carried out in 21 children with AAA (for 18 patients, it was their first HSCT, while 3 had a repeat HSCT): out of these, 11 patients received transplants from matched unrelated donors, 9 received transplants from matched related donors and 1 - from a haploidentical donor. Nine children received calcineurin inhibitor-based graft-versus-host disease prophylaxis while 12 children received Janus kinase inhibitors. A good graft function was achieved in all the children, without any severe complications. As per the latest findings, 95% of the patients achieved full total donor cell chimerism, 85.7% of the patients had full donor chimerism in the CD3+ cell lineage, while 14.3% had mixed CD3+ cell chimerism with 9-13% of own cells. The inclusion of melphalan in a conditioning regimen in patients with AAA before HSCT in combination with new less toxic graft-versus-host disease prophylaxis regimens may be an effective strategy to overcome the risk of graft rejection and ensure a low toxicity profile and low incidence of complications. The study was approved by the Independent Ethics Committee and the Scientific Council of the N.I. Pirogov Russian National Research Medical University of Ministry of Healthcare of the Russian Federation.

A wide use of blood products inevitably leads to an increase in the number of complications associated with it. These complications include thromboembolic events that are considered to be rare and difficult-to-manage. Currently, the mechanisms and possible laboratory predictors of such complications are unclear. This paper presents our experience of using flow cytometry to assess the parameters of phosphatidylserine expression (detected by Annexin V binding) and describes impairments in the deformability of red blood cells (detected using forward and side scatter data) which determine the procoagulant properties of cells. According to our findings, the use of Annexin V for the assessment of gradual cell death in the samples of red blood cell (RBC) suspension is controversial. At the same time, our results show a higher sensitivity of the assessment of the accumulation of RBCs with an altered shape for the detection of programmed cell death - eryptosis. The obtained results can be used to improve the detection of dead RBCs during the routine storage of RBC suspension. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation.

B-ceLL precursors (hematogones) account for Less than 5% of normaL bone marrow (BM) nucLeated ceUs but in some cLinicaL conditions the number of hematogones can be transientLy increased. Their morphoLogy has been characterized in patients with increased numbers of hematogones. However, the scarcity of hematogones and inabiLity to obtain their pure popuLation make it difficuLt to thoroughLy investigate the morphoLogy of these ceLLs in normaL BM. A pure popuLation of hematogones was isoLated as a fraction of CD10⁺ BM mononucLear ceLLs from 14 patients with increased numbers of hematogones and 12 heaLthy donors using microarrays with immobiLized antibodies to duster of differentiation (CD) antigens. We described the main morphoLogicaL subtypes of hematogones of normaL BM and anaLyzed the proportion of these ceUs among CD19+, CD22+, CD20+, and CD10+CD34+ BM mononucLear ceUs. One to nine percent of hematogones are 13-17 mm in diameter and have basophiLic cytopLasm, Lacy or fineLy reticuLated, bLastic chromatin and prominent nucLeoLi. The remaining hematogones are immature Lymphoid ceLLs that vary considerabLy in size (7-15 mm in diameter) and have scanty cytopLasm, smudged chromatin and absent nucLeoLi. Three to twenty-five percent of these ceLLs are Larger than 10 mm. CD10+CD34+ ceLLs do not show predominancy bLastic morphoLogy, however some bLast-Like hematogones express CD20. Hematogones in normaL BM are heterogeneous in morphoLogy and size. We found no apparent correLation between the morphoLogy of hematogones and their stages of maturation. The study was approved by the Independent Ethics Committee and the Scientific CounciL of the Dmitry Rogachev NationaL MedicaL Research Center of Pediatric HematoLogy, OncoLogy and ImmunoLogy of Ministry of HeaLthcare of the Russian Federation. ALL donors and patients gave their informed consent to BM aspiration and participation in future biomedicaL studies.

There are various mechanisms of red blood cell (RBC) clearance from the circulation, including eryptosis and hemolysis. The spleen plays a major role in eliminating RBCs from the blood flow thanks to their ability to pass through narrow spaces. Still, some questions such as the role of phosphatidylserine-binding proteins in this process remain unanswered. Thus, RBC elimination mechanisms are still not very well explored. Here, we report on a flow cytometry protocol using phosphatidylserine markers for the detection of whole blood erythrocytes that can be classified as pre-elimination RBCs. We also provide the results of healthy donors' blood testing suggesting that reliable detection of eryptosis in whole blood is indeed possible. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of Russia.

Hypercholesterolemia is one of the complications of allogeneic hematopoietic stem cell transplantation. Various factors may contribute to its etiology, including graft-versus-host disease (GVHD) of the liver. This publication presents a clinical case of severe hypercholesterolemia associated with acute GVHD with the liver involvement in a patient with Nijmegen syndrome. The patient's parents gave their consent to the use of their child's data, including photographs, for research purposes and in publications. A high level of lipoprotein X was detected by peripheral blood electrophoresis and subsequent typing. This laboratory phenomenon is a characteristic manifestation of dyslipidaemia associated with cholestasis accompanying the hepatic form of GVHD. Clinical improvement and a reduction of cholesterol levels were achieved after intensification of immunosuppressive therapy. This clinical case highlights the necessity for early recognition and differential assessment of severe hypercholesterolemia in patients following allogeneic hematopoietic stem cell transplantation.

The article provides a brief description of a case of St. maltophilia metastatic skin lesion in a child diagnosed with primary immunodeficiency on the background of deep agranulocytosis associated with rejection of an allogeneic hematopoietic stem cell transplant.

Allogeneic hematopoietic stem cell transplantation (HSCT) is a key treatment strategy for life-threatening hematologic and immunologic diseases. Immune reconstitution after allogeneic HSCT is a complex and multistage process, which is critical to the recovery of the patient's immune function and to the reduction of the risk of infectious complications. Studies show that most patients experience a significant improvement in immune function 6-12 months after transplantation; however, a full recovery may take up to 2 years or more. One of the major complications of allogeneic HSCT is prolonged hypogammaglobulinemia - low serum immunoglobulin G levels for more than 2 years after allogeneic HSCT. In the absence of a clearly defined threshold for hypogammaglobulinemia, the generally accepted definition is a serum immunoglobulin G level below 5 g/L. Impaired antibody formation and the occurrence of prolonged hypogammaglobulinemia in children after allogeneic HSCT are complex problems that require careful monitoring and appropriate management. Timely restoration of B cell number and function is critical to reduce the risk of infectious complications and improve the quality of patients' life.

Diamond-Blackfan anaemia is a rare congenital bone marrow failure syndrome characterized by suppression of erythropoiesis due to intense apoptosis of erythroid precursors resulting from defective ribosome biosynthesis. Classic options for the treatment of Diamond-Blackfan anaemia include long-term glucocorticosteroid therapy and transfusion of donor red blood cells. However, these approaches eventually lead to late adverse events, which stimulates the search for alternative therapies. In this paper, we review the current knowledge of the pathogenesis and therapy of this disease.